Misty: An Object-Oriented Programming Language with Multiple Inheritance and Strict Type-Checking

Abstract

Summary A strong type-checking facility is indispensable for an object-oriented programming language to be usable in large-scale software development. Misty is an object-oriented programming language with both multiple inheritance and strict type-checking facilities. Type-checking is applied not according to subtype relations between types, but according to strict equality between types. This principle differs markedly from that of other object-oriented programming languages with “strong” type-checking facilities, which incorporate subtype relations, and Misty's type-checking facility therefore termed a “strict” one. In spite of this strictness, Misty retains most of the flexibility seen in object-oriented programming languages without compile-time type checking. Moreover, experience of programming in Misty has revealed that program design and development using a class specification hierarchy along with a compiler to check its consistency will be a valuable and powerful tool for programming-in-the-large.